Search PubMed⌕ Search

Biomedical subjects

L Trentin

Publications and source records attributed to L Trentin.

At least 91 records · Page 5Linked to original sources

Constitutive production of tumor necrosis factor-alpha in hairy cell leukemia: possible role in the pathogenesis of the cytopenia(s) and effect of treatment with interferon-alpha.

PURPOSE: In view of the pleomorphic role cytokines play in human lymphoproliferative disorders, we investigated the possible involvement of tumor necrosis factor-alpha (TNF) in hairy cell leukemia (HCL). PATIENTS AND METHODS: The levels of TNF were measured in the serum of untreated patients, and in the culture supernatants of unstimulated and stimulated enriched hairy cells (HC). Furthermore, the presence of TNF mRNA transcripts in HC was analyzed. The possibility that HC could inhibit the in vitro growth of normal erythroid progenitors via the release of TNF was also investigated. Finally, in an attempt to correlate the circulating levels of TNF with the course of the disease, these were retested during and after treatment with interferon-alpha (IFN). RESULTS: Significantly increased levels of TNF were found in the sera of untreated HCL patients compared with normal control sera were seen from patients with other diseases (P less than .001), with values greater than 10 pg/mL in 21 of 42 samples tested. A significant decrease (P less than .01) of TNF levels was recorded following IFN-2a administration in 16 cases with detectable pretreatment serum levels of TNF. In two cases, an increase in TNF values was associated with persistence or progression of disease. The likelihood that the circulating levels of TNF were caused by the pathologic cells is supported by the evidence that purified HC may release TNF spontaneously. The values can be markedly increased following in vitro activation with the phorbol ester 12-0-tetradecanoylphorbol-13 acetate (PMA), with B-cell growth factor (BCGF), and, to a further extent, with the combination of PMA and BCGF. Furthermore, the constitutive mRNA for TNF was found in seven of eight HC samples analyzed. Although supernatants of enriched HC, were capable of reducing the growth of normal bone marrow erythroid progenitors by 50%, duplicate experiments using an anti-TNF antibody produced an almost complete disappearance of the inhibitory effect. CONCLUSION: The results of this study suggest that TNF plays an important role in the pathogenesis of the cytopenia(s) characteristically associated with HCL.

Adult↗

Expression of HLA-A2 antigen in human melanoma cell lines and its role in T-cell recognition.

Previous studies have suggested that, in human melanoma, expression of HLA-A2 antigen is important for tumor cell recognition by autologous T-lymphocytes. Because of the recent demonstration that expression of HLA Class I antigens may be selectively lost in several human tumors, including melanoma, we derived pairs of tumor infiltrating lymphocytes (TIL) and melanoma cell lines from 4 human lymphocytic antigen (HLA)-A2+ patients with metastatic melanoma. We observed that, although all 4 TIL cultures expressed HLA-A2 antigen, only 2 melanoma cell lines did so. Melanoma cells derived from the other 2 patients showed neither surface expression of the HLA-A2 antigen nor presence of the corresponding mRNA. We also observed some correlation between loss of HLA-A2 expression and level of c-myc transcription. TIL derived from patients whose melanoma cell lines had normal expression of HLA-A2 had a CD8 phenotype and were capable of lysing autologous melanoma cells. Melanoma cell killing was CD3 and major histocompatibility complex Class I restricted in both cases, but HLA-A2 restricted in only one case. On the other hand, TIL derived from the 2 patients whose melanoma cell lines had lost expression of HLA-A2 had a predominant CD4 phenotype and virtually no cytotoxic activity. Preincubation of the HLA-A2 negative melanoma cell lines with alpha- or gamma-interferon did not induce the re-expression of the HLA-A2 antigen. In an attempt to restore HLA-A2 antigen expression in one of the melanoma cell lines that were HLA-A2 negative, we transfected these cells with the HLA-A2 gene subcloned in the pSV2-neo vector. Four transfected clones, with high levels of HLA-A2 antigen expression, were expanded and characterized. Proliferative and cytotoxic activities of TIL against the autologous transfected clones as well as the untransfected parental melanoma cell line were measured and compared. CD4+ TIL showed no difference in the proliferative response to autologous parental and HLA-A2 transfected clones. However, we observed selective recognition of the HLA-A2 expressing clones by autologous cultured peripheral blood lymphocytes (which contained CD8 cells) as well as allogeneic CD8+ TIL with a HLA-A2 restricted pattern of recognition. In contrast, virtually no cytotoxic activity was detected against either parental or HLA-A2 transfected clones. Overall, our data suggest that selective down-regulation of HLA-A2 antigen expression in melanoma cells may represent one of the mechanisms by which tumor cells escape immunological recognition.

Antibodies, Monoclonal↗

Shedding of the soluble form of the CD8 complex by CD8+/HLA-DR+ cells in HIV-1-infected patients.

High levels of the soluble form of the CD8 molecule (sCD8) are detectable in the serum of HIV-1-infected patients. To investigate the mechanisms accountable for the release of this molecule we evaluated the presence of sCD8 in the supernatants obtained from in vitro cultures of highly purified CD8 cells isolated from 20 HIV-1-infected patients. At resting conditions cultured CD8 cells from HIV-1-infected patients released low amounts of sCD8; no statistically significant differences were observed between unstimulated cultures from HIV-1-seropositive patients and from HIV-1-seronegative subjects at risk for HIV-1 infection or normal healthy controls. Following in vitro activation of highly purified CD8 cells with a series of stimulatory agents, including phorbol myristate acetate, phytohemagglutinin (PHA) and recombinant interleukin-2, CD8 cells of HIV-1-infected patients significantly increased the shedding of sCD8. By expressing the results of activation-related release index (ARRI = sCD8 levels detected in the cultures with stimulatory agent/sCD8 levels detected in the unstimulated cultures), significantly higher values were observed upon PHA stimulation in HIV-1-infected patients than in control subjects. In order to identify the cell subset responsible for the enhanced release of sCD8 by PHA-stimulated cultures, we correlated the amounts of sCD8 detected in the supernatants with the phenotypic profile of CD8+ cells recovered from the cultures. A significant relationship was demonstrated between the percentage of CD8+/HLA-DR+ lymphocytes and sCD8 levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Alveolar macrophages from patients with AIDS and AIDS-related complex constitutively synthesize and release tumor necrosis factor alpha.

To verify the hypothesis that alveolar macrophages (AMs) from patients infected with HIV-1 could synthesize and release TNF alpha, AMs recovered from the BAL fluid of 11 patients with seropositive HIV-1 (six with AIDS and five with ARC) were tested in vitro for their ability to destroy TNF alpha-susceptible targets. Furthermore, the presence of TNF alpha was assessed in AM-conditioned supernatants on the basis of their cytotoxic activity and by using an immunoenzymatic test and immunoblotting. Transcription of the TNF alpha gene in AMs was also studied by means of the Northern blot analysis. AMs freshly recovered from patients infected with HIV-1 exhibited high levels of cell-mediated cytotoxicity against U937 targets, and the addition of a polyclonal anti-TNF alpha antibody resulted in a significant inhibition of the target lysis. Cell-free supernatants conditioned by unstimulated AMs exerted high levels of cytotoxic activity against TNF alpha-sensitive targets, whereas duplicate, neutralization experiments performed in the presence of an anti-TNF alpha antibody proved that the observed cytotoxic activity was mostly mediated by TNF alpha. The presence of high amounts of TNF alpha in the conditioned media was confirmed by the immunoenzymatic test. In addition, the immunoblot analysis showed that the TNF alpha released by AMs has a Mr 17,000 band, identical to a standard preparation of recombinant TNF alpha. The Northern blot demonstrated that unstimulated AMs express detectable levels of mRNA transcripts for TNF alpha. Taken together, our data support the concept that AMs from patients with HIV-1 infection constitutively release TNF alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗

Prognostic significance of the evaluation of bronchoalveolar lavage cell populations in patients with HIV-1 infection and pulmonary involvement.

To investigate the prognostic utility of the morphologic and immunologic evaluation of BAL cell populations in determining mortality risk, we analyzed BAL data obtained from 115 patients infected with HIV-1. Forty fatal outcomes occurred within 73 patients with OI. The OI patients who died showed a significant increase in neutrophils with respect to surviving patients. Furthermore, the finding of a BAL neutrophilia in HIV-1-infected patients with OI strongly correlated with a high risk of death. Among 42 cases without OI, 11 patients died. Patients without OI who had a fatal outcome showed an increase in CD3+ and CD8+ BAL lymphocytes with respect to the survivors. The presence of a lymphocytic alveolitis was associated with a significant increase in the mortality rate. Taken together our data suggest that the evaluation of the BAL cell populations might be useful in predicting the risk of fatal outcome in patients with HIV-1 infection.

Acquired Immunodeficiency Syndrome↗

Tumor necrosis factor-alpha and B-cell growth factor induce leukemic hairy cells to proliferate in vitro.

To clarify the mechanisms accounting for the hairy cell proliferation, in five patients with hairy cell leukemia (HCL), we evaluated the ability of neoplastic cells to proliferate in vitro in response to tumor necrosis factor-alpha (TNF-alpha), B-cell growth factor (BCGF), and interleukin 4 (IL-4). In addition, supernatants recovered from cultures of unstimulated hairy cells were tested for the capability to induce the proliferation of allogeneic hairy cells. We demonstrated that TNF-alpha and BCGF were able to induce the in vitro growth of hairy cells (stimulation index (SI) ranging, at different concentrations, from 1.6 to 10.7 and from 1.6 to 25.1 for TNF-alpha and BCGF, respectively). IL-4 did not show any proliferative effect on hairy cells. When unstimulated hairy cell supernatants were tested for the proliferative activity on allogeneic hairy cells, we demonstrated a low proliferative effect that was not inhibited by an anti-TNF-alpha antibody. Our findings demonstrate that unstimulated hairy cells proliferate in vitro in response to TNF-alpha and BCGF, thus suggesting that these cytokines could be involved in an autocrine model of cell proliferation.

Cell Division↗

Different mechanisms of activation of proliferating CD3+ cells in patients with lymphoproliferative disease of granular lymphocytes.

To investigate the role of p55 and p75 chains of interleukin-2 receptor (IL-2R) on the activation of granular lymphocytes (GL) in patients with lymphoproliferative disease of granular lymphocytes (LDGL), the cells obtained from 11 LDGL patients (belonging to the CD3+ group) were studied for (a) the surface expression and (b) mRNA transcripts of the p55 and p75 IL-2R after activation with anti-CD3 monoclonal antibody (mAb) or interleukin-2 (IL-2). The effects of mAbs specifically blocking the p55 and p75 IL-2R on the generation of proliferative and cytotoxic functions were studied following anti-CD3 mAb stimulation. A significant difference was observed in the expression of p55 and p75 antigens on LDGL cells under resting conditions: a low number of p55 IL-2R+ (mean 1.2 +/- 0.4%) and high values of p75 IL-2R+ cells (54.9 +/- 7.4%). Accordingly, a barely detectable message for the p55 IL-2R and a strong signal for the p75 IL-2R mRNA were demonstrated. Following activation with anti-CD3 or IL-2, different patterns of IL-2R expression were observed. Anti-CD3 mAb induced an increase in the expression of the p55 IL-2R both at the mRNA and antigen level, whereas the p75 values remained consistently raised. In contrast, IL-2 induced the expression of p55 IL-2R mRNA associated with only a slight expression of this antigen. This finding was associated with a decrease in the cell expression of the p75 IL-2R, whereas the amount of p75 mRNA was unchanged. Both anti-CD3 mAb and IL-2 induced cell proliferation and cytotoxicity against the K-562 target cells. Anti-p55 IL-2R mAb did not affect the cytotoxic activity mediated by anti-CD3, but it markedly inhibited cell proliferation. Anti-p75 mAb did not inhibit either lytic function or cell proliferation mediated by anti-CD3 mAb, suggesting that only the high affinity IL-2R (p55 plus p75) is involved in anti-CD3 mediated cell activation in LDGL patients. This mechanism is different from that responsible for the IL-2 activation of CD3+ GL in LDGL patients, which is achieved through the p75 IL-2R alone. These results provide new insights into the pathophysiology of proliferating GL in LDGL patients and may also contribute to further characterization of the normal CD3+ GL population.

Adult↗

Cell membrane expression and functional role of the p75 subunit of interleukin-2 receptor in lymphoproliferative disease of granular lymphocytes.

The cell membrane expression and functional role of the interleukin-2 receptor (IL-2R) was analyzed in nine patients with lymphoproliferative disease of granular lymphocytes (LDGL) using monoclonal antibodies (MoAbs) specific for the p75 (TU27) and the p55 (anti-Tac) subunits of IL-2R. Four patients were characterized by the proliferation of CD3+CD8+ granular lymphocytes (GL) expressing the alpha/beta T-cell receptor (T alpha beta) and one case by the proliferation of CD3+CD4-CD8- GL expressing the gamma/delta T-cell receptor (T gamma delta); in four additional cases proliferating cells were CD3 negative GL. Consistent with data observed on normal GL, phenotypic analysis demonstrated that patients' GL lack the expression of the p55 IL-2R, whereas the p75 subunit is constitutionally expressed by expanding GL of both T-cell (either T alpha beta and T gamma delta) and natural killer (NK) origin in variable proportions (11% to 94% of cells). The analysis of the cytotoxic and proliferative activity demonstrated that the anti-p55 MoAb failed to inhibit IL-2-mediated activation, whereas a marked inhibition of both cytotoxicity and proliferation were obtained using the anti-p75 chain specific MoAb. These data indicate that the p75 chain of IL-2R is responsible for IL-2 signal transduction in both CD3+ and CD3- LDGL patients' GL.

Adult↗

Mechanisms accounting for lymphocytic alveolitis in hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HP) is a lung disorder characterized by an exaggerated accumulation of CD8+ T lymphocytes in the pulmonary parenchyma. To investigate the mechanisms accounting for the T cell alveolitis taking place in the lung of HP patients and their pattern of growth, cells recovered from the bronchoalveolar lavage (BAL) of seven patients were evaluated for: 1) the expression of activation markers, including IL-2R (p55 and p75 subunits), HLA-DR and VLA-1 Ag; 2) the ability of IL-2 and IL-4 to induce in vitro proliferation; 3) the capability to synthesize and release IL-2 by determining the levels of IL-2 in BAL cell-free supernatants and by evaluating the presence of mRNA transcripts for IL-2; and 4) the molecular configuration of the beta- and gamma-genes of the TCR. This study demonstrates that a high number of BAL lymphocytes recovered from the lungs of HP patients express activation markers including the p75 chain of IL-2R, VLA-1, and HLA-DR Ag. These cells express the CD3+,CD8+,CD16-,CD56+ phenotype and proliferate in vitro in the presence of IL-2 but do not release this cytokine. Furthermore, IL-2 transcripts could not be detected in BAL resting T lymphocytes. No proliferation was observed in the presence of IL-4. The analysis of the configuration of the TCR beta- and gamma-genes showed a polyclonal pattern, with the exception of one case in which extra bands were observed following digestion with BamHI and EcoRI restriction enzymes. Taken together, our data suggest that the IL-2 system may play a central role in the mechanisms accounting for lymphocytic alveolitis in HP patients. Although the pattern of growth is usually polyclonal, such polyclonal recruitment seems to be biased toward cells that have rearranged and possibly expressed particular V beta or V gamma genes, thus leading to the hypothesis that the events that take place in the lung of these patients may occasionally elicit an oligoclonal expansion of the cells proliferating in lung parenchyma.

Adult↗

Mechanisms accounting for the defective natural killer activity in patients with hairy cell leukemia.

Natural killer (NK) cell activity is severely impaired in untreated patients with hairy cell leukemia (HCL). In an attempt to investigate whether this impairment is related to a defect at the target cell binding and/or at the post target cell binding level, we evaluated the peripheral blood mononuclear cells (PBMC) of HCL patients for their ability to: (1) bind and kill K-562 NK-sensitive targets at the single cell binding level; (2) release the NK cytotoxic factor (NKCF) under different in vitro stimuli, including K-562 and phytohemoagglutinin; and (3) kill K-562 targets in a lectin-dependent cellular cytoxicity (LDCC) assay. This study demonstrates that untreated HCL patients' PBMC show a low ability to form conjugates with K-562 targets at the single cell binding level (5.7% +/- 1.0%) with respect to patients studied after treatment (9.3% +/- 1.3%) and controls (15.0% +/- 4.0%); P less than .05 and P less than .001, respectively. A decreased ability to kill the bound target was demonstrated in untreated cases (1.2% +/- 1.1%) versus patients studied after treatment and controls (12.3% +/- 1.6%, 17.0% +/- 3.1% respectively); P less than .001 in both conditions. After activation of effector cells with interleukin-2 (IL-2) in vitro, an increase in the ability of PBMC to form conjugates with K-562 targets and kill the bound target was demonstrated in each group of patients. Moreover, IL-2 was able to increase the cytotoxicity against NK-sensitive targets in all patients tested. Evaluation of NKCF production showed that untreated patients release low levels of NKCF when PBMC were incubated in the presence of K-562 stimulators (1.8% +/- 0.7%) with respect to patients after interferon-alpha (IFN-alpha) therapy (7.6% +/- 2.1%) and controls (12.9% +/- 2.2%); P less than .02 and P less than .001, respectively. When the recognition mechanisms were bypassed by triggering the cells with lectins in an LDCC assay, we demonstrated an increase of the lytic activity in both groups of patients with respect to the baseline values. However, the cytotoxic capacity observed in untreated patients was significantly lower than that observed in subjects after IFN-alpha therapy and controls (P less than .001). These findings suggest that the impaired NK activity observed in patients with HCL is related to defects both at the target and posttarget cell binding levels.

Adult↗

Susceptibility to lysis of pulmonary alveolar macrophages by human lymphokine-activated killer cells.

In this study we addressed the question of whether lymphokine-activated killer (LAK) cells, besides killing neoplastic cells, may exert a certain degree of lysis on the normal counterpart; in particular we took into consideration the toxicity against pulmonary alveolar macrophages (PAM). We demonstrated that human LAK cells generated in vitro following incubation of peripheral blood mononuclear cells with recombinant interleukin 2 for 4 days were able to lyse normal PAM in a 4-h 51Cr release assay. Similarly, PAM recovered from patients suffering from nonneoplastic interstitial lung disorders, i.e., sarcoidosis and hypersensitivity pneumonitis, were shown to be susceptible to the cytotoxic function provided by LAK cells. Both autologous and allogeneic PAM were lysed by LAK cells, thus suggesting that the phenomenon we observed does not require a major histocompatibility complex restriction. Preincubation of PAM under study with gamma-interferon did not affect their susceptibility to the lysis mediated by LAK cells. Furthermore, cold target inhibition assay demonstrated that normal PAM could efficiently compete with both NK-sensitive and NK-resistant target lines for the binding sites on LAK cells, thus indicating that the putative receptor(s), or at least the mechanism of target recognition, is shared by PAM and these different target cell lines. The evidence herein provided that LAK cells are cytotoxic to normal, nontransformed PAM points out that the pathogenetic mechanisms involving this self-addressed lytic activity could account for some adverse reactions related to LAK/interleukin 2 immunotherapy.

Cell Line↗

Cytotoxic events taking place in the lung of patients with HIV-1 infection. Evidence of an intrinsic defect of the major histocompatibility complex-unrestricted killing partially restored by the incubation with rIL-2.

To characterize the cytotoxic events taking place in the lung of patients with HIV-1 infection, we studied the cells recovered from the bronchoalveolar lavage (BAL) of nine patients with AIDS, seven patients with AIDS-related complex, and two patients with lymphadenopathy. Phenotypic analysis was coupled to a series of functional evaluations of nonspecific cytotoxic abilities performed on lung effectors, including their property to bind K-562 targets, to release natural killer cytotoxic factor (NKCF), and to become cytotoxic following in vitro activation with rIL-2. Our results demonstrated that lung cells bearing the NK-related CD16, CD56, and CD57 antigens were quantitatively increased, irrespective of the disease stage. The majority of the cells also coexpressed the CD3 molecule and the alpha/beta T cell receptor (TCR), notably the phenotype characterizing MHC-unrestricted cytotoxic T cells. From a functional point of view, a severe impairment of the spontaneous cytotoxic ability was demonstrated in most patients. Evaluation at the single cell level showed a normal percentage of the effector/target conjugates formed by HIV-1 lymphocytes. The release of NKCF was undetectable in patients with AIDS even following lectin stimulation, whereas BAL cells from patients with earlier infection produced and/or could be triggered to release discrete amounts of NKCF by incubation with PHA. Studies designed to activate lung cytotoxic cells with rIL-2 showed that in most patients the stimulation of effector cells with rIL-2 enhanced the spontaneous killing and elicited a lymphokine-activated killer (LAK) phenomenon.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗

[Techniques of celiac plexus block and clinical results].

Coeliac plexus neurolesion techniques for pain due to upper abdominal cancer (pancreas cancer above all), have changed during the years. In this paper we report the results of coeliac plexus alcohol neurolysis for cancer of pancreas and of other abdominal organs achieved with the different techniques. It appears that precrural techniques provide very favorable results but they require the use of CT scan. Retrocrural techniques, while giving good results, can be performed under fluoroscopic control.

Autonomic Nerve Block↗

Evaluation of serum levels of soluble interleukin-2 receptor in patients with chronic lymphoproliferative disorders of T-lymphocytes.

Serum levels of soluble interleukin-2 receptor (sIL-2R) have been evaluated in 33 patients with chronic lymphoproliferative disorders of T-lymphocytes, including 12 T-helper phenotype chronic lymphocytic leukemias (Th-CLL) and 21 lymphoproliferative diseases of granular lymphocytes (LDGL). All Th-CLL cases were negative for antibodies against type I human T-leukemia virus (HTLV-I). Serum levels of sIL-2R were significantly increased in patients with Th-CLL with respect to controls (P less than 0.02) and this increase was related to the clinical course of the disease. In fact, patients with rapidly progressive disease (mean survival, 11.6 +/- 3 months) showed significantly higher concentrations of sIL-2R than patients with less aggressive disease (mean survival, 39.5 +/- 5 months) (16,223 U/ml +/- 5612 versus 1447 U/ml +/- 817; P less than 0.05). A significant positive correlation was found between sIL-2R concentrations and the number of CD4-positive cells (r = 0.64; P less than 0.05). These data point to the possible use of sIL-2R levels as a marker of active malignancy in patients with Th-CLL. Patients with LDGL showed increased sIL-2R values (721 U/ml +/- 112) with respect to controls (334 U/ml +/- 28; P less than 0.005). However, the sIL-2R levels were lower than those detected in Th-CLL patients (P less than 0.05). Among the different correlations the authors tried to establish, the only observed difference was found between serum sIL-2R levels in the group of CD3+ LDGL patients with respect to CD3- LDGL cases (P less than 0.05).

Antigens, CD↗

Functional analysis of cytotoxic cells in patients with acute nonlymphoblastic leukemia in complete remission.

In the current study, we investigated the cytotoxic ability of peripheral blood mononuclear cells (PBMC) recovered from patients with acute nonlymphoblastic leukemia (ANLL) in complete remission (CR) against natural killer (NK)-sensitive, NK-resistant, autologous and allogeneic leukemic target cells taken at diagnosis. Our purpose was to define the role played by cytotoxic mechanisms in the control of leukemic cell growth in ANLL. Experiments were carried out at resting conditions and after in vitro activation with recombinant interleukin-2 (rIL-2) and anti-CD3 monoclonal antibody (moAb). At resting conditions, PBMC recovered from ANLL patients displayed a NK function that was not significantly different from controls (mean +/- standard error of the mean [SEM]: 21.9% +/- 3.9% versus control values of 27.5% +/- 2.9%; the P value was not significant [NS]), but they were unable to show cytotoxic activity against autologous and allogeneic leukemic cells. After in vitro boosting with rIL-2, PBMC were able to generate lymphokine activated killer (LAK) cells, as demonstrated by an increased killing of NK-resistant Daudi targets (16.3% +/- 2.7%). Although LAK activity was quantitatively lower than in control subjects (mean +/- SEM: 16.3% +/- 2.7% versus control values of 79.8% +/- 3.1%; P less than 0.001), it still exerted a cytotoxic effect against autologous and allogeneic leukemic cells. Similar results were obtained when anti-CD3 moAb was used as a stimulus in vitro. Our data suggest that nonspecific cytotoxic cells may be triggered to exert an in vitro cytotoxic effect on leukemic cells, which could possibly play a key role in vivo in the control of leukemic cell growth regulation.

Adult↗